package com.example.tools;

import android.content.Context;
import android.text.Html;
import android.text.Spanned;
import android.util.DisplayMetrics;
import android.view.WindowManager;

import java.util.Arrays;
import java.util.Collections;

/**
 * <pre>
 *     author: Blankj
 *     blog  : http://blankj.com
 *     time  : 2016/8/16
 *     desc  : 字符串相关工具类
 * </pre>
 */
public class StringUtils {

    private StringUtils() {
        throw new UnsupportedOperationException("u can't fuck me...");
    }

    /**
     * 判断字符串是否为null或长度为0
     *
     * @param s 待校验字符串
     * @return {@code true}: 空<br> {@code false}: 不为空
     */
    public static boolean isEmpty(CharSequence s) {
        return s == null || s.length() == 0;
    }

    /**
     * 判断字符串是否为null或全为空格
     *
     * @param s 待校验字符串
     * @return {@code true}: null或全空格<br> {@code false}: 不为null且不全空格
     */
    public static boolean isSpace(String s) {
        return (s == null || s.trim().length() == 0);
    }

    /**
     * null转为长度为0的字符串
     *
     * @param s 待转字符串
     * @return s为null转为长度为0字符串，否则不改变
     */
    public static String null2Length0(String s) {
        return s == null ? "" : s;
    }

    /**
     * 返回字符串长度
     *
     * @param s 字符串
     * @return null返回0，其他返回自身长度
     */
    public static int length(CharSequence s) {
        return s == null ? 0 : s.length();
    }

    /**
     * 首字母大写
     *
     * @param s 待转字符串
     * @return 首字母大写字符串
     */
    public static String upperFirstLetter(String s) {
        if (isEmpty(s) || !Character.isLowerCase(s.charAt(0))) {
            return s;
        }
        return String.valueOf((char) (s.charAt(0) - 32)) + s.substring(1);
    }

    /**
     * 首字母小写
     *
     * @param s 待转字符串
     * @return 首字母小写字符串
     */
    public static String lowerFirstLetter(String s) {
        if (isEmpty(s) || !Character.isUpperCase(s.charAt(0))) {
            return s;
        }
        return String.valueOf((char) (s.charAt(0) + 32)) + s.substring(1);
    }

    /**
     * 反转字符串
     *
     * @param s 待反转字符串
     * @return 反转字符串
     */
    public static String reverse(String s) {
        int len = length(s);
        if (len <= 1) return s;
        int mid = len >> 1;
        char[] chars = s.toCharArray();
        char c;
        for (int i = 0; i < mid; ++i) {
            c = chars[i];
            chars[i] = chars[len - i - 1];
            chars[len - i - 1] = c;
        }
        return new String(chars);
    }

    /**
     * 转化为半角字符
     *
     * @param s 待转字符串
     * @return 半角字符串
     */
    public static String toDBC(String s) {
        if (isEmpty(s)) {
            return s;
        }
        char[] chars = s.toCharArray();
        for (int i = 0, len = chars.length; i < len; i++) {
            if (chars[i] == 12288) {
                chars[i] = ' ';
            } else if (65281 <= chars[i] && chars[i] <= 65374) {
                chars[i] = (char) (chars[i] - 65248);
            } else {
                chars[i] = chars[i];
            }
        }
        return new String(chars);
    }

    /**
     * 转化为全角字符
     *
     * @param s 待转字符串
     * @return 全角字符串
     */
    public static String toSBC(String s) {
        if (isEmpty(s)) {
            return s;
        }
        char[] chars = s.toCharArray();
        for (int i = 0, len = chars.length; i < len; i++) {
            if (chars[i] == ' ') {
                chars[i] = (char) 12288;
            } else if (33 <= chars[i] && chars[i] <= 126) {
                chars[i] = (char) (chars[i] + 65248);
            } else {
                chars[i] = chars[i];
            }
        }
        return new String(chars);
    }

    /**
     * 将指定文字转化颜色
     * @param specimen 想要转化颜色的文字;
     * @param allString  想要转化文字所在的字符串;
     * @param color 想要的颜色 可以英文 可以#0000 样式;
     * @return
     */

    public static Spanned getColorString(String specimen, String allString, String color){
        String [] str = allString.split(specimen);
        StringBuffer buffer = new StringBuffer();
        for (int i = 0 ;i<str.length;i++){
            String strings =  str[i];
            if((str.length-i)==1){
                buffer.append(strings);
            } else {
                buffer.append(strings+"<font color="+color+">"+specimen+"</font>");
            }
        }
        return Html.fromHtml(buffer.toString());
    }

}